From nobody Sat Feb 7 08:45:09 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; envelope-from=libvir-list-bounces@redhat.com; helo=mx1.redhat.com; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1561681793; cv=none; d=zoho.com; s=zohoarc; b=RsVHL7bMv+lapgrNc2jIbBPgYjxluWatVyakBartQz2II9Swz3+8WTZu9hgh11Dtzf26zLKC05GNBU1GATOVNqyNOkvQQGKcunoZEF3wlIHO+q01tkijUj2DfXe9CvCdqU2YFFew4xQhFckFmq37VqixOJNXV/1SFYQQcoQiUiQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1561681793; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=sxxtStTAc6Jr+nUmriUVHfRmgKRnWPQHjWJYuKkF/iA=; b=CWM3yaKDMk8DUfeBN2HpPWoW0tfYF4yd5ZafQ3M5AqfIpVoQ+PYb20jj1LSPIlWAK4i/0yEXyslmlR3Lk7Z96jPd4b5Vyyp6WyfjxP+WhtaPuMVeJ+oNQIpQCBCXXcFLH/B7Uuz19V7TT1UwIKqunBsZXSak+egjUC8AD2rcLBI= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mx.zohomail.com with SMTPS id 1561681793544815.0322459054314; Thu, 27 Jun 2019 17:29:53 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CEB50308A953; Fri, 28 Jun 2019 00:29:42 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE58B1001B17; Fri, 28 Jun 2019 00:29:31 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 9590554D3D; Fri, 28 Jun 2019 00:29:12 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id x5S0T8UA025917 for ; Thu, 27 Jun 2019 20:29:08 -0400 Received: by smtp.corp.redhat.com (Postfix) id E019560C69; Fri, 28 Jun 2019 00:29:08 +0000 (UTC) Received: from localhost (ovpn-116-7.gru2.redhat.com [10.97.116.7]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3448360BE0; Fri, 28 Jun 2019 00:29:05 +0000 (UTC) From: Eduardo Habkost To: qemu-devel@nongnu.org Date: Thu, 27 Jun 2019 21:28:43 -0300 Message-Id: <20190628002844.24894-9-ehabkost@redhat.com> In-Reply-To: <20190628002844.24894-1-ehabkost@redhat.com> References: <20190628002844.24894-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-loop: libvir-list@redhat.com Cc: libvir-list@redhat.com, Igor Mammedov , Jiri Denemark , "Dr. David Alan Gilbert" Subject: [libvirt] [PATCH v2 8/9] docs: Deprecate CPU model runnability guarantees X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Fri, 28 Jun 2019 00:29:46 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Document that CPU model runnability guarantees won't apply to unversioned CPU models anymore. Signed-off-by: Eduardo Habkost Reviewed-by: Daniel P. Berrang=C3=A9 --- Changes v1 -> v2: * (none) Cc: libvir-list@redhat.com --- qemu-deprecated.texi | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index 9cba82d5ec..18f85f70e1 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -276,3 +276,22 @@ Note that if you are exposing the export via /dev/nbd0= , it is easier to just export the entire image and then mount only /dev/nbd0p1 than it is to reinvoke @command{qemu-nbd -c /dev/nbd0} limited to just a subset of the image. + +@section Backwards compatibility + +@subsection Runnability guarantee of CPU models (since 4.1.0) + +Previous versions of QEMU never changed existing CPU models in +ways that introduced additional host software or hardware +requirements to the VM. This allowed management software to +safely change the machine type of an existing VM without +introducing new requirements ("runnability guarantee"). This +prevented CPU models from being updated to include CPU +vulnerability mitigations, leaving guests vulnerable in the +default configuration. + +The CPU model runnability guarantee won't apply anymore to +existing CPU models. Management software that needs runnability +guarantees must resolve the CPU model aliases using te +``alias-of'' field returned by the ``query-cpu-definitions'' QMP +command. --=20 2.18.0.rc1.1.g3f1ff2140 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list